The major overall goals of this project are (1) to study mechanisms involved in fibroblast chemotaxis, (2) to characterize components of connective tissue, lymphokines and complement that modulate fibroblast synthesis of collagen, glycosaminoglycans, collagenase and fibroblast proliferation and (3) determine the nature and influence of a 240,000 MW fibroblast chemotaxis inhibitor on fibroblast metabolic activity. During the first year of this project, we have optimized and modified the Peterkofsky and Diegelmann assay for collagen synthesis by fibroblasts, characterized and isolated human lymphokines that modulate fibroblast proliferation, chemotaxis, and synthesis of collagen, and have partially purified the 240,000 MW serum inhibitor of fibroblast chemotaxis. As a result of these studies, we have observed a new lymphokine effect on fibroblast, namely, aggregation. These data thus far suggest that mechanisms by which lymphocytes modulate fibroblast activity are complex and are mediated via soluble products synthesized during lymphocyte stimulation.